<?php
/**
 * Zend Framework
 *
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 *
 * @category   Zend
 * @package    Zend_Pdf
 * @copyright  Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 * @version    $Id: Tiff.php 18993 2009-11-15 17:09:16Z alexander $
 */

/** Internally used classes */
require_once 'Zend/Pdf/Element/Array.php';
require_once 'Zend/Pdf/Element/Name.php';
require_once 'Zend/Pdf/Element/Numeric.php';


/** Zend_Pdf_Resource_Image */
require_once 'Zend/Pdf/Resource/Image.php';

/**
 * TIFF image
 *
 * @package    Zend_Pdf
 * @copyright  Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */
class Zend_Pdf_Resource_Image_Tiff extends Zend_Pdf_Resource_Image
{
	const TIFF_FIELD_TYPE_BYTE=1;
	const TIFF_FIELD_TYPE_ASCII=2;
	const TIFF_FIELD_TYPE_SHORT=3;
	const TIFF_FIELD_TYPE_LONG=4;
	const TIFF_FIELD_TYPE_RATIONAL=5;

	const TIFF_TAG_IMAGE_WIDTH=256;
	const TIFF_TAG_IMAGE_LENGTH=257; //Height
	const TIFF_TAG_BITS_PER_SAMPLE=258;
	const TIFF_TAG_COMPRESSION=259;
	const TIFF_TAG_PHOTOMETRIC_INTERPRETATION=262;
	const TIFF_TAG_STRIP_OFFSETS=273;
	const TIFF_TAG_SAMPLES_PER_PIXEL=277;
	const TIFF_TAG_STRIP_BYTE_COUNTS=279;

	const TIFF_COMPRESSION_UNCOMPRESSED = 1;
	const TIFF_COMPRESSION_CCITT1D = 2;
	const TIFF_COMPRESSION_GROUP_3_FAX = 3;
	const TIFF_COMPRESSION_GROUP_4_FAX  = 4;
	const TIFF_COMPRESSION_LZW = 5;
	const TIFF_COMPRESSION_JPEG = 6;
	const TIFF_COMPRESSION_FLATE = 8;
	const TIFF_COMPRESSION_FLATE_OBSOLETE_CODE = 32946;
	const TIFF_COMPRESSION_PACKBITS = 32773;

	const TIFF_PHOTOMETRIC_INTERPRETATION_WHITE_IS_ZERO=0;
	const TIFF_PHOTOMETRIC_INTERPRETATION_BLACK_IS_ZERO=1;
	const TIFF_PHOTOMETRIC_INTERPRETATION_RGB=2;
	const TIFF_PHOTOMETRIC_INTERPRETATION_RGB_INDEXED=3;
	const TIFF_PHOTOMETRIC_INTERPRETATION_CMYK=5;
	const TIFF_PHOTOMETRIC_INTERPRETATION_YCBCR=6;
	const TIFF_PHOTOMETRIC_INTERPRETATION_CIELAB=8;

	protected $_width;
	protected $_height;
	protected $_imageProperties;
	protected $_endianType;
	protected $_fileSize;
	protected $_bitsPerSample;
	protected $_compression;
	protected $_filter;
	protected $_colorCode;
	protected $_whiteIsZero;
	protected $_blackIsZero;
	protected $_colorSpace;
	protected $_imageDataOffset;
	protected $_imageDataLength;

	const TIFF_ENDIAN_BIG=0;
	const TIFF_ENDIAN_LITTLE=1;

	const UNPACK_TYPE_BYTE=0;
	const UNPACK_TYPE_SHORT=1;
	const UNPACK_TYPE_LONG=2;
	const UNPACK_TYPE_RATIONAL=3;

	/**
	 * Byte unpacking function
	 *
	 * Makes it possible to unpack bytes in one statement for enhanced logic readability.
	 *
	 * @param int $type
	 * @param string $bytes
	 * @throws Zend_Pdf_Exception
	 */
	protected function unpackBytes($type, $bytes) {
		if(!isset($this->_endianType)) {
			require_once 'Zend/Pdf/Exception.php';
			throw new Zend_Pdf_Exception("The unpackBytes function can only be used after the endianness of the file is known");
		}
		switch($type) {
			case Zend_Pdf_Resource_Image_Tiff::UNPACK_TYPE_BYTE:
				$format = 'C';
				$unpacked = unpack($format, $bytes);
				return $unpacked[1];
				break;
			case Zend_Pdf_Resource_Image_Tiff::UNPACK_TYPE_SHORT:
				$format = ($this->_endianType == Zend_Pdf_Resource_Image_Tiff::TIFF_ENDIAN_LITTLE)?'v':'n';
				$unpacked = unpack($format, $bytes);
				return $unpacked[1];
				break;
			case Zend_Pdf_Resource_Image_Tiff::UNPACK_TYPE_LONG:
				$format = ($this->_endianType == Zend_Pdf_Resource_Image_Tiff::TIFF_ENDIAN_LITTLE)?'V':'N';
				$unpacked = unpack($format, $bytes);
				return $unpacked[1];
				break;
			case Zend_Pdf_Resource_Image_Tiff::UNPACK_TYPE_RATIONAL:
				$format = ($this->_endianType == Zend_Pdf_Resource_Image_Tiff::TIFF_ENDIAN_LITTLE)?'V2':'N2';
				$unpacked = unpack($format, $bytes);
				return ($unpacked[1]/$unpacked[2]);
				break;
		}
	}

	/**
	 * Object constructor
	 *
	 * @param string $imageFileName
	 * @throws Zend_Pdf_Exception
	 */
	public function __construct($imageFileName)
	{
		if (($imageFile = @fopen($imageFileName, 'rb')) === false ) {
			require_once 'Zend/Pdf/Exception.php';
			throw new Zend_Pdf_Exception( "Can not open '$imageFileName' file for reading." );
		}

		$byteOrderIndicator = fread($imageFile, 2);
		if($byteOrderIndicator == 'II') {
			$this->_endianType = Zend_Pdf_Resource_Image_Tiff::TIFF_ENDIAN_LITTLE;
		} else if($byteOrderIndicator == 'MM') {
			$this->_endianType = Zend_Pdf_Resource_Image_Tiff::TIFF_ENDIAN_BIG;
		} else {
			require_once 'Zend/Pdf/Exception.php';
			throw new Zend_Pdf_Exception( "Not a tiff file or Tiff corrupt. No byte order indication found" );
		}

		$version = $this->unpackBytes(Zend_Pdf_Resource_Image_Tiff::UNPACK_TYPE_SHORT, fread($imageFile, 2));

		if($version != 42) {
			require_once 'Zend/Pdf/Exception.php';
			throw new Zend_Pdf_Exception( "Not a tiff file or Tiff corrupt. Incorrect version number." );
		}
		$ifdOffset = $this->unpackBytes(Zend_Pdf_Resource_Image_Tiff::UNPACK_TYPE_LONG, fread($imageFile, 4));

		$fileStats = fstat($imageFile);
		$this->_fileSize = $fileStats['size'];

		/*
		 * Tiff files are stored as a series of Image File Directories (IFD) each direcctory
		 * has a specific number of entries each 12 bytes in length. At the end of the directories
		 * is four bytes pointing to the offset of the next IFD.
		 */

		while($ifdOffset > 0) {
			if(fseek($imageFile, $ifdOffset, SEEK_SET) == -1 || $ifdOffset+2 >= $this->_fileSize) {
				require_once 'Zend/Pdf/Exception.php';
				throw new Zend_Pdf_Exception("Could not seek to the image file directory as indexed by the file. Likely cause is TIFF corruption. Offset: ". $ifdOffset);
			}

			$numDirEntries = $this->unpackBytes(Zend_Pdf_Resource_Image_Tiff::UNPACK_TYPE_SHORT, fread($imageFile, 2));

			/*
			 * Since we now know how many entries are in this (IFD) we can extract the data.
			 * The format of a TIFF directory entry is:
			 *
			 * 2 bytes (short) tag code; See TIFF_TAG constants at the top for supported values. (There are many more in the spec)
			 * 2 bytes (short) field type
			 * 4 bytes (long) number of values, or value count.
			 * 4 bytes (mixed) data if the data will fit into 4 bytes or an offset if the data is too large.
			 */
			for($dirEntryIdx = 1; $dirEntryIdx <= $numDirEntries; $dirEntryIdx++) {
				$tag         = $this->unpackBytes(Zend_Pdf_Resource_Image_Tiff::UNPACK_TYPE_SHORT, fread($imageFile, 2));
				$fieldType   = $this->unpackBytes(Zend_Pdf_Resource_Image_Tiff::UNPACK_TYPE_SHORT, fread($imageFile, 2));
				$valueCount  = $this->unpackBytes(Zend_Pdf_Resource_Image_Tiff::UNPACK_TYPE_LONG, fread($imageFile, 4));

				switch($fieldType) {
					case Zend_Pdf_Resource_Image_Tiff::TIFF_FIELD_TYPE_BYTE:
						$fieldLength = $valueCount;
						break;
					case Zend_Pdf_Resource_Image_Tiff::TIFF_FIELD_TYPE_ASCII:
						$fieldLength = $valueCount;
						break;
					case Zend_Pdf_Resource_Image_Tiff::TIFF_FIELD_TYPE_SHORT:
						$fieldLength = $valueCount * 2;
						break;
					case Zend_Pdf_Resource_Image_Tiff::TIFF_FIELD_TYPE_LONG:
						$fieldLength = $valueCount * 4;
						break;
					case Zend_Pdf_Resource_Image_Tiff::TIFF_FIELD_TYPE_RATIONAL:
						$fieldLength = $valueCount * 8;
						break;
					default:
						$fieldLength = $valueCount;
				}

				$offsetBytes = fread($imageFile, 4);

				if($fieldLength <= 4) {
					switch($fieldType) {
						case Zend_Pdf_Resource_Image_Tiff::TIFF_FIELD_TYPE_BYTE:
							$value = $this->unpackBytes(Zend_Pdf_Resource_Image_Tiff::UNPACK_TYPE_BYTE, $offsetBytes);
							break;
						case Zend_Pdf_Resource_Image_Tiff::TIFF_FIELD_TYPE_ASCII:
							//Fall through to next case
						case Zend_Pdf_Resource_Image_Tiff::TIFF_FIELD_TYPE_LONG:
							$value = $this->unpackBytes(Zend_Pdf_Resource_Image_Tiff::UNPACK_TYPE_LONG, $offsetBytes);
							break;
						case Zend_Pdf_Resource_Image_Tiff::TIFF_FIELD_TYPE_SHORT:
							//Fall through to next case
						default:
							$value = $this->unpackBytes(Zend_Pdf_Resource_Image_Tiff::UNPACK_TYPE_SHORT, $offsetBytes);
					}
				} else {
					$refOffset = $this->unpackBytes(Zend_Pdf_Resource_Image_Tiff::UNPACK_TYPE_LONG, $offsetBytes);
				}
				/*
				 * Linear tag processing is probably not the best way to do this. I've processed the tags according to the
				 * Tiff 6 specification and make some assumptions about when tags will be < 4 bytes and fit into $value and when
				 * they will be > 4 bytes and require seek/extraction of the offset. Same goes for extracting arrays of data, like
				 * the data offsets and length. This should be fixed in the future.
				 */
				switch($tag) {
					case Zend_Pdf_Resource_Image_Tiff::TIFF_TAG_IMAGE_WIDTH:
						$this->_width = $value;
						break;
					case Zend_Pdf_Resource_Image_Tiff::TIFF_TAG_IMAGE_LENGTH:
						$this->_height = $value;
						break;
					case Zend_Pdf_Resource_Image_Tiff::TIFF_TAG_BITS_PER_SAMPLE:
						if($valueCount>1) {
							$fp = ftell($imageFile);
							fseek($imageFile, $refOffset, SEEK_SET);
							$this->_bitsPerSample = $this->unpackBytes(Zend_Pdf_Resource_Image_Tiff::UNPACK_TYPE_SHORT, fread($imageFile, 2));
							fseek($imageFile, $fp, SEEK_SET);
						} else {
							$this->_bitsPerSample = $value;
						}
						break;
					case Zend_Pdf_Resource_Image_Tiff::TIFF_TAG_COMPRESSION:
						$this->_compression = $value;
						switch($value) {
							case Zend_Pdf_Resource_Image_Tiff::TIFF_COMPRESSION_UNCOMPRESSED:
								$this->_filter = 'None';
								break;
							case Zend_Pdf_Resource_Image_Tiff::TIFF_COMPRESSION_CCITT1D:
								//Fall through to next case
							case Zend_Pdf_Resource_Image_Tiff::TIFF_COMPRESSION_GROUP_3_FAX:
								//Fall through to next case
							case Zend_Pdf_Resource_Image_Tiff::TIFF_COMPRESSION_GROUP_4_FAX:
								$this->_filter = 'CCITTFaxDecode';
								require_once 'Zend/Pdf/Exception.php';
								throw new Zend_Pdf_Exception("CCITTFaxDecode Compression Mode Not Currently Supported");
								break;
							case Zend_Pdf_Resource_Image_Tiff::TIFF_COMPRESSION_LZW:
								$this->_filter = 'LZWDecode';
								require_once 'Zend/Pdf/Exception.php';
								throw new Zend_Pdf_Exception("LZWDecode Compression Mode Not Currently Supported");
								break;
							case Zend_Pdf_Resource_Image_Tiff::TIFF_COMPRESSION_JPEG:
								$this->_filter = 'DCTDecode'; //Should work, doesnt...
								require_once 'Zend/Pdf/Exception.php';
								throw new Zend_Pdf_Exception("JPEG Compression Mode Not Currently Supported");
								break;
							case Zend_Pdf_Resource_Image_Tiff::TIFF_COMPRESSION_FLATE:
								//fall through to next case
							case Zend_Pdf_Resource_Image_Tiff::TIFF_COMPRESSION_FLATE_OBSOLETE_CODE:
								$this->_filter = 'FlateDecode';
								require_once 'Zend/Pdf/Exception.php';
								throw new Zend_Pdf_Exception("ZIP/Flate Compression Mode Not Currently Supported");
								break;
							case Zend_Pdf_Resource_Image_Tiff::TIFF_COMPRESSION_PACKBITS:
								$this->_filter = 'RunLengthDecode';
								break;
						}
						break;
					case Zend_Pdf_Resource_Image_Tiff::TIFF_TAG_PHOTOMETRIC_INTERPRETATION:
						$this->_colorCode = $value;
						$this->_whiteIsZero = false;
						$this->_blackIsZero = false;
						switch($value) {
							case Zend_Pdf_Resource_Image_Tiff::TIFF_PHOTOMETRIC_INTERPRETATION_WHITE_IS_ZERO:
								$this->_whiteIsZero = true;
								$this->_colorSpace = 'DeviceGray';
								break;
							case Zend_Pdf_Resource_Image_Tiff::TIFF_PHOTOMETRIC_INTERPRETATION_BLACK_IS_ZERO:
								$this->_blackIsZero = true;
								$this->_colorSpace = 'DeviceGray';
								break;
							case Zend_Pdf_Resource_Image_Tiff::TIFF_PHOTOMETRIC_INTERPRETATION_YCBCR:
								//fall through to next case
							case Zend_Pdf_Resource_Image_Tiff::TIFF_PHOTOMETRIC_INTERPRETATION_RGB:
								$this->_colorSpace = 'DeviceRGB';
								break;
							case Zend_Pdf_Resource_Image_Tiff::TIFF_PHOTOMETRIC_INTERPRETATION_RGB_INDEXED:
								$this->_colorSpace = 'Indexed';
								break;
							case Zend_Pdf_Resource_Image_Tiff::TIFF_PHOTOMETRIC_INTERPRETATION_CMYK:
								$this->_colorSpace = 'DeviceCMYK';
								break;
							case Zend_Pdf_Resource_Image_Tiff::TIFF_PHOTOMETRIC_INTERPRETATION_CIELAB:
								$this->_colorSpace = 'Lab';
								break;
							default:
								require_once 'Zend/Pdf/Exception.php';
								throw new Zend_Pdf_Exception('TIFF: Unknown or Unsupported Color Type: '. $value);
						}
						break;
					case Zend_Pdf_Resource_Image_Tiff::TIFF_TAG_STRIP_OFFSETS:
						if($valueCount>1) {
							$format = ($this->_endianType == Zend_Pdf_Resource_Image_Tiff::TIFF_ENDIAN_LITTLE)?'V*':'N*';
							$fp = ftell($imageFile);
							fseek($imageFile, $refOffset, SEEK_SET);
							$stripOffsetsBytes = fread($imageFile, $fieldLength);
							$this->_imageDataOffset = unpack($format, $stripOffsetsBytes);
							fseek($imageFile, $fp, SEEK_SET);
						} else {
							$this->_imageDataOffset = $value;
						}
						break;
					case Zend_Pdf_Resource_Image_Tiff::TIFF_TAG_STRIP_BYTE_COUNTS:
						if($valueCount>1) {
							$format = ($this->_endianType == Zend_Pdf_Resource_Image_Tiff::TIFF_ENDIAN_LITTLE)?'V*':'N*';
							$fp = ftell($imageFile);
							fseek($imageFile, $refOffset, SEEK_SET);
							$stripByteCountsBytes = fread($imageFile, $fieldLength);
							$this->_imageDataLength = unpack($format, $stripByteCountsBytes);
							fseek($imageFile, $fp, SEEK_SET);
						} else {
							$this->_imageDataLength = $value;
						}
						break;
					default:
						//For debugging. It should be harmless to ignore unknown tags, though there is some good info in them.
						//echo "Unknown tag detected: ". $tag . " value: ". $value;
				}
			}
			$ifdOffset = $this->unpackBytes(Zend_Pdf_Resource_Image_Tiff::UNPACK_TYPE_LONG, fread($imageFile, 4));
		}

		if(!isset($this->_imageDataOffset) || !isset($this->_imageDataLength)) {
			require_once 'Zend/Pdf/Exception.php';
			throw new Zend_Pdf_Exception("TIFF: The image processed did not contain image data as expected.");
		}

		$imageDataBytes = '';
		if(is_array($this->_imageDataOffset)) {
			if(!is_array($this->_imageDataLength)) {
				require_once 'Zend/Pdf/Exception.php';
				throw new Zend_Pdf_Exception("TIFF: The image contained multiple data offsets but not multiple data lengths. Tiff may be corrupt.");
			}
			foreach($this->_imageDataOffset as $idx => $offset) {
				fseek($imageFile, $this->_imageDataOffset[$idx], SEEK_SET);
				$imageDataBytes .= fread($imageFile, $this->_imageDataLength[$idx]);
			}
		} else {
			fseek($imageFile, $this->_imageDataOffset, SEEK_SET);
			$imageDataBytes = fread($imageFile, $this->_imageDataLength);
		}
		if($imageDataBytes === '') {
			require_once 'Zend/Pdf/Exception.php';
			throw new Zend_Pdf_Exception("TIFF: No data. Image Corruption");
		}

		fclose($imageFile);

		parent::__construct();

		$imageDictionary = $this->_resource->dictionary;
		if(!isset($this->_width) || !isset($this->_width)) {
			require_once 'Zend/Pdf/Exception.php';
			throw new Zend_Pdf_Exception("Problem reading tiff file. Tiff is probably corrupt.");
		}

		$this->_imageProperties = array();
		$this->_imageProperties['bitDepth'] = $this->_bitsPerSample;
		$this->_imageProperties['fileSize'] = $this->_fileSize;
		$this->_imageProperties['TIFFendianType'] = $this->_endianType;
		$this->_imageProperties['TIFFcompressionType'] = $this->_compression;
		$this->_imageProperties['TIFFwhiteIsZero'] = $this->_whiteIsZero;
		$this->_imageProperties['TIFFblackIsZero'] = $this->_blackIsZero;
		$this->_imageProperties['TIFFcolorCode'] = $this->_colorCode;
		$this->_imageProperties['TIFFimageDataOffset'] = $this->_imageDataOffset;
		$this->_imageProperties['TIFFimageDataLength'] = $this->_imageDataLength;
		$this->_imageProperties['PDFfilter'] = $this->_filter;
		$this->_imageProperties['PDFcolorSpace'] = $this->_colorSpace;

		$imageDictionary->Width            = new Zend_Pdf_Element_Numeric($this->_width);
		if($this->_whiteIsZero === true) {
			$imageDictionary->Decode       = new Zend_Pdf_Element_Array(array(new Zend_Pdf_Element_Numeric(1), new Zend_Pdf_Element_Numeric(0)));
		}
		$imageDictionary->Height           = new Zend_Pdf_Element_Numeric($this->_height);
		$imageDictionary->ColorSpace       = new Zend_Pdf_Element_Name($this->_colorSpace);
		$imageDictionary->BitsPerComponent = new Zend_Pdf_Element_Numeric($this->_bitsPerSample);
		if(isset($this->_filter) && $this->_filter != 'None') {
			$imageDictionary->Filter = new Zend_Pdf_Element_Name($this->_filter);
		}

		$this->_resource->value = $imageDataBytes;
		$this->_resource->skipFilters();
	}
	/**
	 * Image width (defined in Zend_Pdf_Resource_Image_Interface)
	 */
	public function getPixelWidth() {
		return $this->_width;
	}

	/**
	 * Image height (defined in Zend_Pdf_Resource_Image_Interface)
	 */
	public function getPixelHeight() {
		return $this->_height;
	}

	/**
	 * Image properties (defined in Zend_Pdf_Resource_Image_Interface)
	 */
	public function getProperties() {
		return $this->_imageProperties;
	}
}

